Glaucoma, What you should know about it.

What is glaucoma?
Glaucoma is a group of diseases that can damage the eye’s optic nerve and result in vision loss and blindness. However, with early treatment, you can often protect your eyes against serious vision loss.


What is the optic nerve?
The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina to the brain. (See diagram below.) The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.

How does open-angle glaucoma damage the optic nerve? In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber and nourishes nearby tissues. The fluid leaves the chamber at the open angle where the cornea and iris meet. (See diagram below.) When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye. Sometimes, when the fluid reaches the angle, it passes too slowly through the meshwork drain. As the fluid builds up, the pressure inside the eye rises to a level that may damage the optic nerve. When the optic nerve is damaged from increased pressure, open-angle glaucoma—and vision loss—may result. That’s why controlling pressure inside the eye is important.

Does increased eye pressure mean that I have glaucoma?
Not necessarily. Increased eye pressure means you are at risk for glaucoma, but does not mean you have the disease. A person has glaucoma only if the optic nerve is damaged. If you have increased eye pressure but no damage to the optic nerve, you do not have glaucoma. However, you are at risk. Follow the advice of your eye care professional.

Can I develop glaucoma if I have increased eye pressure?
Not necessarily. Not every person with increased eye pressure will develop glaucoma. Some people can tolerate higher eye pressure better than others. Also, a certain level of eye pressure may be high for one person but normal for another. Whether you develop glaucoma depends on the level of pressure your optic nerve can tolerate without being damaged. This level is different for each person. That’s why a comprehensive dilated eye exam is very important. It can help your eye care professional determine what level of eye pressure is normal for you.

Can I develop glaucoma without an increase in my eye pressure?
Yes. Glaucoma can develop without increased eye pressure. This form of glaucoma is called low-tension or normal-tension glaucoma. It is not as common as open-angle glaucoma.

Who is at risk for open-angle glaucoma?
Anyone can develop glaucoma. Some people are at higher risk than others.
They include:
• African Americans over age 40.
• Everyone over age 60, especially Mexican Americans.
• People with a family history of glaucoma.

A comprehensive dilated eye exam can reveal more risk factors, such as high eye pressure, thinness of the cornea, and abnormal optic nerve anatomy. In some people with certain combinations of these high-risk factors, medicines in the form of eyedrops reduce the risk of developing glaucoma by about half.

What are the symptoms of glaucoma?
At first, open-angle glaucoma has no symptoms. It causes no pain. Vision stays normal. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. They seem to be looking through a tunnel. Over time, straight-ahead vision may decrease until no vision remains. Glaucoma can develop in one or both eyes.

Can glaucoma be cured?
No. There is no cure for glaucoma. Vision lost from the disease cannot be restored.

Can glaucoma be treated?
Yes. Immediate treatment for early stage, open-angle glaucoma can delay progression of the disease. That’s why early diagnosis is very important.